William r



(No Model.) W. R. PATTERSON.

ANTI-INDUCTION CABLE. No. 252,611. Patented Jan.17,18 82.

N4 PcTERa Fhoto-Limognphor, Washington, :1. c.

UNITED STATES PATENT OFFICE.

WILLIAM PATTERSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE WEST- ERN ELECTRIC MANUFACTURING COMPANY, OF SAME PLAOEJ A NTI-INDUCTION CABLE.

SPECIFICATION forming part of'Letters Patent No. 252,511, dated January 17,. 1882.

' Application filed July 14, 1881. (No model.)

To all whom it may concern:

I Be itknown that. I, WILLIAM R. PATTER- SON, of Chicago, county of Cook, Illinois, have discovered a certain new and useful Improve- 5 ment in Anti-Induction Gables, of which the following is a full, clear, concise, and exact description.

My improvement consists in combining a circuit of low resistance with the telephoneline circuits in such manner as to neutralize the effect of the secondary currents. Prior to my invention this circuit of low resistance was formed, in whole or in part, of metallicsheaths wrapped about the insulating-coverings of the different conductors. The establishment of a current in any conductor causes an induced currentin the opposite direction in all the other circuits, including the low-resistance circuit.

It follows from Ohms law that, the current being equal to the electro-motive force divided by the resistance, a much greater tertiary current will be induced from the circuit of low resistance than from any of the others. I find that when the resistance of this circuit is very low in comparison with that of any of the others-say from one-tenth to one-fifteenth, or less-this tertiary current will practically neutralize the secondary currents in the small condoctors.

o In the drawings, Figure 1. is'a diagram of the circuits of a telegraph-cable embodying my improvements. Fig. 2 is a transverse section of a cable containing many telephone-lines and the wire of low resistance.

3 5. The telephone-line may be closed to battery 1,475 of 1880, and United States Letters Patent 5 5,

No. 231,085, to H. G. Pearson, dated August 10, 1880, and No. 242,651, to W. W.'Jaques, dated June 7, 1881.

I elaim' 1. The combination of a complete metallic 6o circuit of ,low resistance placed in the interior ofthe cable among the other conductors, with one of said conductors used as aprimary circuit and several of said conductors used as secondary circuits, whereby the elfeets of iuduction are overcome, substantially as and for the purpose specified.

2. In a telegraph-cable, the combination of separately insulated conducting: wires with a complete metallic circuit of low resistance, which is placedceutrally among the said conducting-wires, as and for the purpose set forth.

3.- A telegraph-cable containing several primary wires, in combination with a complete metallic circuit of low resistance placed dentrally among the other conductors, whereby tertiary currents are induced, as and for the purpose set forth,

4. Thecombination of primary line a, key a,

orits equivalent, oneor several secondary lines,

b, and the'low-resistance wire 0, whereby tertiary currents are induced in said line or lines I), as and for the purpose set forth.

WILLIAM R. PATTERSON. 

